Fig. 82 Fig. 83 Fig. 84
The basic text is by the instrument's designer, Orsini, augmented by extensive annotations by Danti, formerly cosmographer to Cosimo I de' Medici, but by the time of this publication in the service of Pope Gregory XIII. This example was a presentation copy from Danti and it has been in the library of the Collegio Romano.
The radio latino has five jointed arms engraved with scales, which can be arranged in different configurations depending on the intended application. The tract explains a wide range of functions, including military applications to gunnery and surveying. The details of the design allude to its military associations, for when folded it fits into a scabbard for carrying on a belt. The military surveyor or the gunner can thus draw his radio latino as readily as his sword.